Intramedullary nailing device

Abstract

The present invention provides an intramedullary nail device, comprising: a first nail body; a second nail body obliquely inserted through the first end of the first nail body; and a third nail body obliquely inserted through the middle of the first nail body, the third nail body supporting the second nail body so that a triangular area is defined between the first, second, and third nail bodies, wherein the third nail body comprises a first nail body segment and a second nail body segment movably engaged with the first nail body segment, the first end of the first nail body segment supporting the second nail body, the second nail body segment inserted through the middle of the first nail body, and a buffer cylinder disposed between the second end of the first nail body segment and the first end of the second nail body segment. The technical solution of the present application effectively solves the problem of intramedullary nails implanted in the femur being cut out of the femur in the related art.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an intramedullary nail device. Background Art

[0002] Proximal femoral fractures (femoral neck and intertrochanteric fractures) account for 90% of hip fractures. Elderly patients often have concurrent osteoporosis, and the proportion of unstable intertrochanteric fractures after trauma is increasing.

[0003] Intertrochanteric fractures are typically treated with intramedullary femoral nailing, which is less likely to experience postoperative fixation failure. Femoral intramedullary nailing can reconnect the fracture site, promote healing, and reduce complications. While widely used for intertrochanteric fractures, actual use has shown a high rate of fixation failure.

[0004] like Figure 1 As shown, the important structures for maintaining the stability of the proximal femur include the medial wall 1, lateral wall 2 and superior wall 3 of the proximal femur, forming a triangle-like shape.

[0005] The triangular support structure formed by normal bone tissue is significantly more stable than the lever-like structure formed by an intramedullary nail. Intramedullary nails are made of metal and are rigid structures. This creates stress shielding for the bone during compression (due to the high elastic modulus of the femoral system), which can easily cause the nail to cut out of the femur or cause internal fixation failure. Summary of the Invention

[0006] The main purpose of the present invention is to provide an intramedullary nail device to solve the problem in the related art that the intramedullary nail implanted in the femur is cut out of the femur.

[0007] In order to achieve the above-mentioned objectives, the present invention provides an intramedullary nail device, comprising: a first nail body; a second nail body, obliquely arranged through the first end of the first nail body; a third nail body, obliquely arranged through the middle of the first nail body, the third nail body supporting the second nail body so that a triangular area is defined between the first nail body, the second nail body and the third nail body, wherein the third nail body comprises a first nail body segment and a second nail body segment movably matched with the first nail body segment, the first end of the first nail body segment supports the second nail body, the second nail body segment is arranged through the middle of the first nail body, and a buffer cylinder is arranged between the second end of the first nail body segment and the first end of the second nail body segment.

[0008] Furthermore, the buffer cylinder includes a cylinder body and a piston rod passing through the cylinder body, one of the piston rod and the cylinder body is arranged on the second end of the first nail body segment, and the other is arranged on the first end of the second nail body segment.

[0009] Furthermore, a first anti-rotation portion is provided on the side wall of the second end of the first nail body segment of the piston rod or on the side wall of the first end of the second nail body segment, and a second anti-rotation portion cooperating with the first anti-rotation portion is provided on the side wall of the cylinder body.

[0010] Furthermore, the piston rod is arranged on the end face of the second end of the first nail body segment, the cylinder body is arranged on the first end of the second nail body segment, the second end of the first nail body segment is sleeved outside the cylinder body, the first anti-rotation part includes an axial groove arranged on the inner wall of the second end of the first nail body segment, and the second anti-rotation part includes an axial rib that is plugged into the axial groove.

[0011] Furthermore, the piston rod includes a piston located in the cylinder body and a rod body connected to the piston, the rod body is inserted into the mounting hole of the cylinder body, and the intramedullary nail device also includes a sealing member arranged between the rod body and the mounting hole.

[0012] Furthermore, the piston divides the inner cavity of the cylinder to form a first chamber and a second chamber, and a flow hole connecting the first chamber and the second chamber is provided on the piston.

[0013] Furthermore, the intramedullary nail device further includes an elastic member disposed between the second end of the first nail body segment and the first end of the second nail body segment.

[0014] Furthermore, the cylinder body is arranged on the first end of the second nail body segment, the axial rib is arranged at the end of the cylinder body, and the intramedullary nail device also includes an elastic member arranged between the second end of the first nail body segment and the first end of the second nail body segment, the elastic member includes a spring sleeved outside the cylinder body, and the spring is located between the axial rib and the first end of the second nail body segment; wherein, the piston rod and the first nail body segment are split structures and are connected by welding, bonding or screwing, and the cylinder body and the second nail body segment are split structures and are connected by welding, bonding or screwing.

[0015] Furthermore, the first nail body segment includes a first polished rod segment and a first threaded segment connected to the first polished rod segment, the piston rod is connected to the first polished rod segment, and the first threaded segment supports the second nail body; the second nail body segment includes a second polished rod segment, a third polished rod segment and a second threaded segment connected between the second polished rod segment and the third polished rod segment, the outer diameter of the second polished rod segment is smaller than the outer diameter of the outer wall of the third polished rod segment, the cylinder body is connected to the second polished rod segment, and one end of the third polished rod segment provided with an operating hole forms the second end of the second nail body segment.

[0016] Furthermore, the first end of the second nail body is provided with an external thread, the second end of the second nail body is provided with an operating groove, and the first end of the first nail body segment supports the external thread; the first nail body includes a third nail body segment and a fourth nail body segment connected to the third nail body segment, the outer diameter of the third nail body segment is larger than the outer diameter of the fourth nail body segment, the second nail body is passed through the first end of the third nail body segment, and the first end of the second nail body segment and the second end of the second nail body segment are respectively located on both sides of the second end of the third nail body segment; the intramedullary nail device also includes a transverse nail passed through the fourth nail body segment.

[0017] Applying the technical solution of the present invention, the intramedullary nail device includes: a first nail body, a second nail body and a third nail body. The second nail body is obliquely inserted into the first end of the first nail body. The third nail body is obliquely inserted into the middle of the first nail body. The third nail body supports the second nail body so that a triangular area is defined between the first nail body, the second nail body and the third nail body. The third nail body includes a first nail body segment and a second nail body segment that is movably matched with the first nail body segment, the first end of the first nail body segment supports the second nail body, the second nail body segment is inserted into the middle of the first nail body, and a buffer cylinder is provided between the second end of the first nail body segment and the first end of the second nail body segment. During the process of implanting the intramedullary nail device into the femur, the first nail body is driven in, the second nail body is inserted into the first end of the first nail body, the fracture end is pressurized by the second nail body, the third nail body is inserted into the middle of the first nail body, and the third nail body supports the second nail body. After implantation of the intramedullary nail device, the first end of the first nail body segment is compressed, and the buffer cylinder between the second end of the first nail body segment and the first end of the second nail body segment is compressed and retracted, generating a damping force on the first nail body segment. The second end of the first nail body segment gradually approaches the first end of the second nail body segment, causing the overall length of the third nail body to gradually decrease. The pressure energy exerted on the intramedullary nail device is stored and dispersed by the buffer cylinder. The retraction of the buffer cylinder slows down and weakens the instantaneous load exerted on the intramedullary nail device, reducing the elastic modulus of the intramedullary nail device and stress shielding. This effectively reconstructs the "Ward triangle" and achieves a stable support intramedullary nail device. This not only effectively reduces and fixes the patient's femoral head, but also reconstructs the "Ward triangle" at the trochanteric region. It also better distributes the stress exerted on the femur, preventing the implanted intramedullary nail device from cutting out of the femur. Therefore, the technical solution of the present application can solve the problem of implanted intramedullary nails cutting out of the femur in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 Schematic diagram showing the "ward triangle" formed under theoretical mechanics analysis of the proximal femur in the related art;

[0020] Figure 2 A perspective schematic diagram showing an intramedullary nail device according to an embodiment of the present invention being implanted into a femur;

[0021] Figure 3 Shown Figure 2 A schematic front view of an intramedullary nail device;

[0022] Figure 4 Shown Figure 2 A schematic cross-sectional view of an intramedullary nail device;

[0023] Figure 5 Shown Figure 2 A schematic diagram of the three-dimensional structure of the third nail body of the intramedullary nail device;

[0024] Figure 6 Shown Figure 5 A schematic cross-sectional view of a third nail body;

[0025] Figure 7 Shown Figure 5 A schematic diagram of the exploded structure of the third nail body;

[0026] Figure 8 Shown Figure 5 A schematic diagram of the exploded structure of the third nail body from another angle;

[0027] Figure 9 Shown Figure 8 A schematic cross-sectional view of the third nail body after decomposition from another angle; and

[0028] Figure 10 Shown Figure 2 A schematic front view of a first nail body of an intramedullary nail device;

[0029] Figure 11 Shown Figure 2 A schematic front view of the second nail body of the intramedullary nail device.

[0030] The above drawings include the following reference numerals:

[0031] 1. Inner wall; 2. Outer wall; 3. Upper wall; 4. Femur; 10. First nail body; 11. Third nail body segment; 12. Fourth nail body segment; 20. Second nail body; 21. External thread; 22. Operating groove; 211. First rod portion; 212. Second rod portion; 213. First stop groove; 214. Second stop groove; 216. Screw thread; 201. First groove; 23. Second groove; 30. Third nail body; 31. First nail body section; 311, first polished rod section; 312, first threaded section; 32, second nail body section; 321, second polished rod section; 322, third polished rod section; 3221, operating hole; 323, second threaded section; 34, axial groove; 35, axial rib; 40, buffer cylinder; 41, cylinder body; 42, piston rod; 421, piston; 4211, flow hole; 422, rod body; 50, transverse nail; 60, elastic member. DETAILED DESCRIPTION

[0032] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] Unless otherwise specifically stated, the relative arrangement of the parts and steps, the numerical expressions and the numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values should be interpreted as being merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0035] like Figures 2 to 6 and Figure 10 As shown, the intramedullary nail device of this embodiment includes: a first nail body 10, a second nail body 20 and a third nail body 30. The second nail body 20 is obliquely inserted into the first end of the first nail body 10. The third nail body 30 is obliquely inserted into the middle of the first nail body 10. The third nail body 30 supports the second nail body 20 so that a triangular area is defined between the first nail body 10, the second nail body 20 and the third nail body 30. The third nail body 30 includes a first nail body segment 31 and a second nail body segment 32 that is movably matched with the first nail body segment 31. The first end of the first nail body segment 31 supports the second nail body 20, and the second nail body segment 32 is inserted into the middle of the first nail body 10. A buffer cylinder 40 is provided between the second end of the first nail body segment 31 and the first end of the second nail body segment 32.

[0036] Using the technical solution of this embodiment, the third nail body 30 includes a first nail body segment 31 and a second nail body segment 32 that movably cooperates with the first nail body segment 31. The first end of the first nail body segment 31 supports the second nail body 20, and the second nail body segment 32 is disposed through the middle of the first nail body 10. A buffer cylinder 40 is disposed between the second end of the first nail body segment 31 and the first end of the second nail body segment 32. During implantation of the intramedullary nail device into the femur, the first nail body is driven in, the second nail body is disposed through the first end of the first nail body, and the second nail body applies pressure to the fractured end. The third nail body is disposed through the middle of the first nail body and supports the second nail body. After implantation of the intramedullary nail device, the first end of the first nail body segment is compressed, and the buffer cylinder 40 between the second end of the first nail body segment and the first end of the second nail body segment is compressed and retracted, generating a damping force on the first nail body segment. The second end of the first nail body segment gradually approaches the first end of the second nail body segment, causing the overall length of the third nail body 30 to gradually decrease. The pressure energy exerted on the intramedullary nail device is stored and dispersed by the buffer cylinder 40. The retraction of the buffer cylinder 40 slows down and reduces the instantaneous load on the intramedullary nail device, lowering its elastic modulus and reducing stress shielding. This effectively reconstructs the "Ward triangle" and achieves a stable intramedullary nail device. This not only effectively reduces and fixes the patient's femoral head, but also reconstructs the "Ward triangle" at the trochanteric region. It also better distributes stress on the femur, preventing the implanted intramedullary nail device from cutting out of the femur. Therefore, the technical solution of this embodiment can solve the problem of implanted intramedullary nails cutting out of the femur in related technologies.

[0037] It should be noted that the middle portion of the first nail body 10 refers to the position between the first end of the first nail body 10 and the second end of the first nail body 10. In this embodiment, the second nail body 20 mainly supports the tension trabeculae in the femur, and the third nail body 30 mainly supports the tensile trabeculae in the femur.

[0038] like Figures 6 to 9 As shown, the buffer cylinder 40 includes a cylinder body 41 and a piston rod 42 extending through the cylinder body 41. The piston rod 42 is disposed on the second end of the first nail body segment 31, and the cylinder body 41 is disposed on the first end of the second nail body segment 32. In this embodiment, the buffering medium within the cylinder body 41 is oil or gas. When the first end of the first nail body segment 31 is pressurized and the second end of the first nail body segment 31 moves relative to the first end of the second nail body segment, the piston rod 42 on the second end of the first nail body segment 31 compresses the buffering medium within the cylinder body 41. The buffering medium cushions the piston rod 42, effectively generating a damping force on the first nail body segment.

[0039] In an embodiment not shown in the figures, the buffer cylinder includes a cylinder body and a piston rod passing through the cylinder body. The cylinder body is arranged on the second end of the first nail body segment, and the piston rod is arranged on the first end of the second nail body segment.

[0040] like Figures 4 to 8 As shown, during the process of inserting the third nail body 30 through the middle portion of the first nail body 10 and screwing it into the femur, to prevent relative rotation between the second nail body segment 32 and the first nail body segment 31, a first rotation stop is provided on the side wall of the second end of the first nail body segment 31, on which the piston rod 42 is provided, and a second rotation stop that cooperates with the first rotation stop is provided on the side wall of the cylinder body 41. Thus, due to the rotational cooperation between the second rotation stop and the first rotation stop, when the second nail body segment 32 is screwed in, the first nail body segment 31 can rotate along with the second nail body segment 32, thereby allowing the third nail body 30 to be inserted through the middle portion of the first nail body 10 and allowing the first end of the first nail body segment 31 to support the second nail body 20.

[0041] In an embodiment not shown in the figures, a first anti-rotation portion may be provided on the side wall of the first end of the second nail body section of the piston rod, and a second anti-rotation portion cooperating with the first anti-rotation portion may be provided on the side wall of the cylinder body.

[0042] like Figures 6 to 9 As shown, the piston rod 42 is disposed on the end surface of the second end of the first body segment 31, and the cylinder 41 is disposed on the first end of the second body segment 32. The second end of the first body segment 31 is sleeved outside the cylinder 41. Thus, the inner hole at the second end of the first body segment 31 and the cylinder 41 provide a guiding fit, allowing the cylinder 41 to move along the axis of the second end of the first body segment 31, preventing the cylinder 41 from deflecting during movement. The first anti-rotation feature includes an axial groove 34 provided on the inner wall of the second end of the first body segment 31, and the second anti-rotation feature includes an axial rib 35 that engages with the axial groove 34. Thus, when the first body segment 31 is subjected to force and moves relative to the second body segment 32, the axial rib 35 can move within the axial groove 34, providing a guiding function. Simultaneously, the sidewalls of the axial groove 34 contact the sidewalls of the axial rib 35, preventing the first body segment 31 from rotating relative to the second body segment 32.

[0043] like Figures 6 to 9 As shown, four axial grooves 34 are spaced apart circumferentially along the second end of the first nail body segment 31, and four axial ribs 35 are spaced apart circumferentially along the first end of the second nail body segment 32. The four axial grooves 34 correspond to the four axial ribs 35. This ensures that when the second nail body segment 32 twists the first nail body segment 31, the third nail body 30 has sufficient structural strength and stability. The number of axial grooves 34 and axial ribs 35 is not limited to four, and can also be one, two, three, five, or more.

[0044] like Figure 4 and Figure 6As shown, the piston rod 42 includes a piston 421 located within the cylinder body 41 and a rod body 422 connected to the piston 421. The rod body 422 is disposed through the mounting hole of the cylinder body 41. The intramedullary nail device also includes a seal disposed between the rod body 422 and the mounting hole. The seal can seal between the rod body 422 and the mounting hole to ensure that the buffer medium does not leak from between the rod body 422 and the mounting hole.

[0045] like Figure 4 、 Figure 6 and Figure 9 As shown, in this embodiment, the buffer medium within the cylinder 41 is oil, and the piston 421 separates the inner cavity of the cylinder 41 to form a first chamber and a second chamber. The piston 421 is provided with a flow hole 4211 connecting the first chamber and the second chamber. When the first end of the first nail body segment is pressurized, the oil in the first chamber flows into the second chamber through the flow hole 4211. At this time, the friction between the inner cavity wall of the cylinder 41 and the oil, as well as the internal friction between the oil molecules, creates a damping force on the vibration, achieving the conversion of kinetic energy, thereby converting the kinetic energy of the buffer cylinder 40 into oil heat, thereby slowing down and weakening the instantaneous load borne by the buffer cylinder 40, allowing the third nail body 30 to effectively reduce the stress borne by the intramedullary nail device.

[0046] like Figures 3 to 6 As shown, the intramedullary nail device further includes an elastic member 60 disposed between the second end of the first nail body segment 31 and the first end of the second nail body segment 32. When the first end of the first nail body segment is compressed, the compression force can overcome the elastic force of the elastic member 60. During the movement of the second end of the first nail body segment 31 relative to the first end of the second nail body segment, the elastic member 60 and the buffer cylinder 40 simultaneously provide a damping force, effectively slowing down and reducing the instantaneous load borne by the intramedullary nail device. The pressure energy borne by the intramedullary nail device is stored and dispersed by the buffer cylinder 40 and the elastic member 60, effectively reducing the possibility of stress concentration in the intramedullary nail device and extending the service life of the intramedullary nail device. When the first end of the first nail body segment is not under pressure or the pressure disappears, an elastic force is applied to the second end of the first nail body segment 31 in a direction away from the first end of the second nail body segment 32 through the elastic member 60. The elastic force drives the first end of the first nail body segment to move in a direction away from the first end of the second nail body segment 32. At this time, the buffer cylinder 40 between the second end of the first nail body segment and the first end of the second nail body segment is not under pressure and is in an extended state, that is, the second end of the first nail body segment 31 gradually moves away from the first end of the second nail body segment, and the oil in the second chamber flows back to the first chamber through the flow hole 4211, so that the third nail body 30 is in an unpressurized initial state.

[0047] like Figures 6 to 9As shown, the cylinder 41 is disposed on the first end of the second nail body segment 32, and the axial rib 35 is disposed at the end of the cylinder 41. The intramedullary nail device also includes an elastic member 60 disposed between the second end of the first nail body segment 31 and the first end of the second nail body segment 32. The elastic member 60 includes a spring that is sleeved outside the cylinder 41 and positioned between the axial rib 35 and the first end of the second nail body segment 32. The axial rib 35 and the second nail body segment 32 respectively constrain one end of the spring, limiting the spring's range of movement outside the cylinder 41 and preventing it from escaping from the cylinder 41. The spring has a simple structure and low installation and design costs. When the first end of the first nail body segment is compressed, the pressure can overcome the elastic force of the elastic member 60. During the movement of the second end of the first nail body segment 31 relative to the first end of the second nail body segment, the second end of the first nail body segment 31 pushes on the spring, which is then squeezed by the second end of the first nail body segment 31 and the first end of the second nail body segment 32, causing the spring to be compressed.

[0048] In this embodiment, the elastic member 60 and the movement of the buffer cylinder are used to slow down and reduce the instantaneous load borne by the intramedullary nail device, so that the third nail body 30 can provide a certain elastic support, making the intramedullary nail device elastic, effectively reducing the possibility of stress concentration in the intramedullary nail device, and extending the service life of the intramedullary nail device. Specifically, the intramedullary nail device is located at the proximal end of the femur 4, that is, the proximal end of the femur.

[0049] For the convenience of connection, processing and assembly, the piston rod 42 and the first nail body section 31 are split structures and are connected by welding, bonding or screwing. For the convenience of connection, processing and assembly, the cylinder body 41 and the second nail body section 32 are split structures and are connected by welding, bonding or screwing.

[0050] In this embodiment, the retraction of the buffer cylinder 40 and the compression of the elastic member 60 effectively slow down and reduce the instantaneous load borne by the intramedullary nail device, so that the third nail body 30 can provide a certain elastic support, making the intramedullary nail device elastic, and effectively reducing the possibility of stress concentration in the intramedullary nail device. Specifically, the intramedullary nail device is located at the proximal end of the femur 4, that is, the proximal end of the femur.

[0051] like Figures 2 to 4As shown, the first nail body segment 31 includes a first polished rod segment 311 and a first threaded segment 312 connected to the first polished rod segment 311. The piston rod 42 is connected to the first polished rod segment 311, and the first threaded segment 312 supports the second nail body 20. Thus, the provision of the first threaded segment 312 facilitates screwing of the first nail body segment 31 into the femur and supports the second nail body 20, ensuring reliable implant stability for the first nail body segment 31. The provision of the first polished rod segment 311 reduces resistance generated during screwing of the first nail body segment 31 into the femur, allowing the first nail body segment 31 to be smoothly screwed into the position where the first threaded segment 312 supports the second nail body 20. The second nail body segment 32 includes a second polished rod segment 321, a third polished rod segment 322, and a second threaded segment 323 connected between the second polished rod segment 321 and the third polished rod segment 322. The outer diameter of the second polished rod segment 321 is smaller than the outer diameter of the outer wall of the third polished rod segment 322. The cylinder body 41 is connected to the second polished rod segment 321. One end of the third polished rod segment 322, which is provided with an operating hole 3221, forms the second end of the second nail body segment 32. Thus, the provision of the second threaded segment 323 facilitates the connection of the second nail body segment 32 to the first nail body 10. The provision of the second polished rod segment 321 and the third polished rod segment 322 can reduce the resistance generated during the screwing of the second nail body segment 32 into the femur, allowing the second nail body segment 32 to be smoothly screwed into the middle portion of the first nail body 10 where the second nail body segment 32 is provided. The setting of the operating hole 3221 facilitates driving the third rod segment 322 to rotate. The operating hole 3221 is preferably an internal hexagonal hole. In this way, an internal hexagonal wrench can be inserted into the operating hole 3221 and can drive the second nail body segment 32 to rotate, so that the third nail body 30 can achieve the effect of reducing and pressurizing the fracture end.

[0052] like Figures 2 to 4 As shown, the first end of the second nail body 20 is provided with an external thread 21, the second end of the second nail body 20 is provided with an operating groove 22, and the first end of the first nail body segment 31 supports the external thread 21. The provision of the external thread 21 facilitates the screwing of the second nail body 20 into the femur, and the provision of the operating groove 22 facilitates operation. The first thread segment 312 supports the external thread 21 and can be engaged and locked, thereby improving the supporting effect of the third nail body 30. After the second nail body 20 is implanted in the femur 4, the second end of the second nail body 20 can be exposed to the outer wall of the femur 4, so that the operating groove 22 on the second end of the second nail body 20 can also be exposed outside the femur 4. The operating groove 22 can be driven using a screwdriver tool.

[0053] like Figure 4 and Figure 11As shown, the external thread 21 includes a shank portion and a screw thread 216 disposed on the shank portion, and the screw thread 216 is provided with a plurality of first grooves 201. When the second nail body 20 is subjected to force, the external thread 21 of the second nail body 20 compresses the bone in the femur when screwed in. The screw thread 216 provided with the plurality of first grooves 201 makes the screw thread 216 elastic and can produce micro-deformation, thereby reducing the elastic modulus of the intramedullary locking nail assembly, allowing the screw thread 216 to adapt to the surrounding bone, so that the bone surrounding the screw thread 216 is inserted into the first grooves 201 for occlusal locking, reducing stress shielding, and effectively preventing further bone cutting and the second nail body 20 from penetrating out of the femur.

[0054] like Figure 4 and Figure 11 As shown, the external thread 21 of the second nail body 20 compresses the bone in the femur when it is screwed in. Since the multiple first grooves 201 located on the same circle of screw teeth 216 are arranged radially, so that each first groove 201 is adapted to the embedded bone, the radial arrangement of the multiple first grooves 201 can bite more bone while reducing the elastic modulus of the second nail body 20, so that the screw teeth 216 can effectively adapt to the surrounding bone.

[0055] It should be noted that the radial arrangement of the plurality of first trenches 201 means that the sidewalls of the plurality of first trenches 201 may diverge along a straight line direction or a curved line direction.

[0056] like Figure 4 and Figure 11 As shown, the height of the screw thread 216 of the external thread 21 gradually decreases from away from the first nail body 10 to closer to the first nail body 10. In this way, the screw thread 216 of the external thread 21 is higher in the portion away from the first nail body 10, and is embedded deeper in the bone, and can bite the bone. At the same time, because the screw thread 216 of the external thread 21 is lower in the portion close to the first nail body 10, it is stronger, which can provide sufficient strength for the screw thread 216 in the portion away from the first nail body 10.

[0057] like Figure 4 and Figure 11As shown, the rod portion includes a first rod portion 211 and a second rod portion 212, the first rod portion 211 being a polished rod structure, and the portion of the second rod portion 212 located between two adjacent screw threads 216 being provided with a plurality of second grooves 23. In this way, during the process of compressing the bone in the femur when the external thread 21 of the second nail body 20 is screwed in, since the first rod portion 211 is a polished rod structure, the resistance to screwing in of the external thread 21 can be reduced, making it easier for the screw threads 216 on the first rod portion 211 to be screwed into deeper bone, while allowing more bone to be embedded in the plurality of first grooves 201 and the plurality of second grooves 23, so that the elastic modulus of the second nail body 20 is closer to the elastic modulus of the bone, satisfying the adaptive condition of the screw threads 216 and its surrounding bone, further preventing bone cutting and the second nail body 20 from passing out to the outside of the femur 4.

[0058] like Figure 4 and Figure 11 As shown, to better enable the threaded teeth 216 on the rod portion to engage and lock, the axial dimension of the first rod portion 211 is greater than the axial dimension of the second rod portion 212. A first stop groove 213 is provided on the first rod portion 211, and a second stop groove 214 is provided on the second rod portion 212, which communicates with the first stop groove 213. The end of the first threaded segment 312 is located within the first and second stop grooves 213, 214. The first and second stop grooves 213, 214, respectively, constrain the ends of the third nail body 30, preventing misalignment when the third nail body 30 supports the second nail body 20, thereby ensuring that the third nail body 30 is securely in its supporting position.

[0059] like Figures 2 to 4 and Figure 10 As shown, the first nail body 10 includes a third nail body segment 11 and a fourth nail body segment 12 connected to the third nail body segment 11. The outer diameter of the third nail body segment 11 is larger than that of the fourth nail body segment 12. The second nail body 20 is disposed through the first end of the third nail body segment 11, and the first end and second end of the second nail body segment 32 are located on either side of the second end of the third nail body segment 11. This ensures that the third polished rod segment 322 is longer, ensuring that after the third nail body 30 is implanted in the femur 4, the second end of the third polished rod segment 322 can be exposed to the lateral wall of the femur 4, allowing the operating hole 3221 in the third polished rod segment 322 to be exposed to the outside of the femur 4. Furthermore, since the outer diameter of the third nail body segment is larger than that of the fourth nail body segment, the third nail body segment has sufficient structural strength, facilitating the installation of the second nail body 20 and the third nail body 30 on the third nail body segment. The intramedullary nail device also includes a transverse nail 50 disposed through the fourth nail body segment 12. The transverse nail 50 is provided to facilitate locking the fourth nail body segment 12 into the femur, thereby improving the overall structural stability of the intramedullary nail device.

[0060] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0061] For ease of description, spatially relative terms such as "above," "on the upper surface of," "on top of," etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "on top of" other devices or structures would then be positioned as "below" or "below" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0062] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0063] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An intramedullary nail device, characterized in that: include: A first nail body (10); A second nail body (20) is obliquely inserted through the first end of the first nail body (10); The third nail body (30) is obliquely inserted into the middle of the first nail body (10), and the third nail body (30) supports the second nail body (20) so that a triangular area is defined between the first nail body (10), the second nail body (20) and the third nail body (30). The third nail body (30) comprises a first nail body segment (31) and a second nail body segment (32) movably matched with the first nail body segment (31); the first end of the first nail body segment (31) supports the second nail body (20); the second nail body segment (32) is passed through the middle of the first nail body (10); and a buffer cylinder (40) is provided between the second end of the first nail body segment (31) and the first end of the second nail body segment (32); The buffer cylinder (40) comprises a cylinder body (41) and a piston rod (42) passing through the cylinder body (41), one of the piston rod (42) and the cylinder body (41) being arranged on the second end of the first nail body segment (31), and the other being arranged on the first end of the second nail body segment (32); the intramedullary nail device further comprises an elastic member (60) arranged between the second end of the first nail body segment (31) and the first end of the second nail body segment (32); the elastic member (60) comprises a spring sleeved outside the cylinder body (41); A first anti-rotation portion is provided on the side wall of the second end of the first nail body segment (31) on which the piston rod (42) is provided, or on the side wall of the first end of the second nail body segment (32), and a second anti-rotation portion that cooperates with the first anti-rotation portion is provided on the side wall of the cylinder body (41); The piston rod (42) includes a piston (421) located in the cylinder body (41) and a rod body (422) connected to the piston (421), the rod body (422) is arranged at the mounting hole of the cylinder body (41), and the intramedullary nail device also includes a sealing member arranged between the rod body (422) and the mounting hole; The buffer medium in the cylinder (41) is oil. The piston (421) separates the inner cavity of the cylinder (41) to form a first chamber and a second chamber. The piston (421) is provided with a flow hole (4211) communicating with the first chamber and the second chamber.

2. The intramedullary nail device according to claim 1, characterized in that: The piston rod (42) is arranged on the end surface of the second end of the first nail body segment (31), the cylinder body (41) is arranged on the first end of the second nail body segment (32), the second end of the first nail body segment (31) is sleeved outside the cylinder body (41), the first anti-rotation portion includes an axial groove (34) arranged on the inner wall of the second end of the first nail body segment (31), and the second anti-rotation portion includes an axial rib (35) plugged into the axial groove (34).

3. The intramedullary nail device according to claim 2, characterized in that: The axial rib (35) is provided at the end of the cylinder (41), and the spring is located between the axial rib (35) and the first end of the second nail body segment (32); The piston rod (42) and the first nail body segment (31) are separate structures and are connected by welding, bonding or screwing, and the cylinder body (41) and the second nail body segment (32) are separate structures and are connected by welding, bonding or screwing.

4. The intramedullary nail device according to claim 1, characterized in that: The first nail body segment (31) comprises a first polished rod segment (311) and a first threaded segment (312) connected to the first polished rod segment (311); the piston rod (42) is connected to the first polished rod segment (311); and the first threaded segment (312) supports the second nail body (20); The second nail body segment (32) comprises a second polished rod segment (321), a third polished rod segment (322), and a second threaded segment (323) connected between the second polished rod segment (321) and the third polished rod segment (322); the outer diameter of the second polished rod segment (321) is smaller than the outer diameter of the outer wall of the third polished rod segment (322); the cylinder (41) is connected to the second polished rod segment (321); and one end of the third polished rod segment (322) provided with the operating hole (3221) forms the second end of the second nail body segment (32).

5. The intramedullary nail device according to claim 1, characterized in that: The first end of the second nail body (20) is provided with an external thread (21), the second end of the second nail body (20) is provided with an operating groove (22), and the first end of the first nail body segment (31) supports the external thread (21); The first nail body (10) comprises a third nail body segment (11) and a fourth nail body segment (12) connected to the third nail body segment (11); the outer diameter of the third nail body segment (11) is larger than the outer diameter of the fourth nail body segment (12); the second nail body (20) is passed through the first end of the third nail body segment (11); the first end of the second nail body segment (32) and the second end of the second nail body segment (32) are respectively located on both sides of the second end of the third nail body segment (11); The intramedullary nail device further comprises a transverse nail (50) passing through the fourth nail body section (12).

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